University Park, Pa. -- The tangled web of fact and fiction swirling in the wake of Arizona's recently enacted immigration law should strike a familiar chord in Pennsylvania, say the authors of a new book about the role of rumors in American history and culture.

In "The Global Grapevine: Why Rumors of Terrorism, Immigration and Trade Matter," Bill Ellis, professor emeritus of English and American studies at Penn State Hazleton, and Gary Alan Fine, professor of sociology at Northwestern University, contend that Americans historically have perceived threats to their economy and culture from abroad. Today's forces of globalization have heightened that anxiety.

"We show that rumors constantly change faces to respond to new situations," said Ellis, citing immigration as one of the globalizing forces.

"In Arizona, the rumors focus on drug trafficking, violent crime, and other threats to the community allegedly posed by Mexican illegals. A hundred and fifty years ago in Pennsylvania, it was the Irish who were seen as a threat to society."

Fraternal groups formed in the state's anthracite coal region by newly arrived Irish immigrants were widely believed to be a front for a terrorist organization known as the Mollie Maguires. This possibly mythical crime conspiracy, according to Ellis, was as feared in its time as Al Qaeda is today. The Mollies were blamed for a wave of murder, intimidation and vandalism in the region until a series of trials in 1876-78 led to some 20 executions.

"Historians agree that some Irish immigrants committed many violent acts, but the claim that they operated as a terrorist society was likely a convenient fiction for companies wanting to quash emerging labor unions," Ellis said.

As an example of how rumors change faces, Ellis and Fine note that in 2006 in the same region, Latino immigrants became the target of an official crusade after a meat-packing plant near Hazleton attracted a large number of Latinos seeking employment. Following a murder in which two Latinos were implicated, rumors began to fly. In a rush to restore public trust, the city council passed an "Illegal Immigration Relief Act," which made landlords and employers liable to severe fines if found harboring undocumented workers.

The Relief Act led to a brief national controversy before it was struck down by a Federal judge. In a way that anticipated the recent Arizona debate, proponents hailed the new Hazleton statute as a solution to the tangled immigrant issue, while others criticized it as racist.

"It really was neither," said Ellis, who resided in the Hazleton area during the dispute. "It was what folklorists call a 'rumor-panic,' in which the community proves to itself that it is still in control through a symbolic act." The statute in fact made people feel that authorities could cope with the changes. Ironically, a follow-up survey determined that the core values and concerns of Latino newcomers were virtually identical to those of the existing residents who had responded so negatively to their arrival.

Ellis and Fine write that "rumor allows us to discuss hidden fears and desires without claiming these attitudes as our own," and explain that rumors provide comfort for people in uncertain and troubling times. Some may even be close to the truth.

"But they are political dynamite," Ellis emphasized, "and they can lead to wrongheaded crusades and even impromptu uses of deadly force. For instance, in the book we discuss the 2008 beating death of Luis Ramirez in Shenandoah, Schuylkill County, by a mob of locals shouting 'This is Shenandoah!' 'This is America!' 'Go back to Mexico!'"

"The Global Grapevine: Why Rumors of Terrorism, Immigration and Trade Matter" is published by Oxford University Press.